Convertible trailer

ABSTRACT

A snowmobile trailer convertible to a sled which can be towed by the snowmobile. The trailer includes skiis which are retractible for highway travel of the trailer. A unique lock mechanism locks the skiis in position and also provides the proper form of connection between the draw bar and frame of the trailer to facilitate loading and to assure that the trailer is used properly.

Minted States Patent 1 [111 3,73n542 Chadwick [451 May 1, 1973 I 1CONVERTIBLE TRAILER 3,584,753 6/1971 Voeller ..214 505 [76] Inventor:Charlie F. Chadwick, R.R. No. l,

Minot Primary Examiner-Benjamin Hersh Assistant Examiner-Robert R. Song[22] filed May 1970 Att0rney-Walter Kruger [2]] Appl. No.: 39,037

ABSTRACT v [52] U.S. Cl. ..280/9, 214/505, 280/494 A snowmobile trailerconvertible to a sled which can [51 Int. Cl. ..B62b 13/18 be towed bythe snowmobile. The trailer includes skiis [58] ld f a h -280/8, l0, 1which are retractible for highway travel of the trailer. 280/13, 414 R,414 214/505, 5 A unique lock mechanism locks the skiis in position andalso provides the proper form of connection [56] References C'tedbetween the draw bar and frame of the trailer to UNITED STATES PATENTSfacilitalte loading and to assure that the trailer is used proper y.3,010,73l 11/196] Kenney ..280/9 3,503,620 3/1970 Koskovich ..280/1 1 11Claims, 10 Drawing Figures.

CONVERTIBLE TRAILER This invention relates to a vehicle which isconvertible from a wheeled vehicle to a sled.

More particularly, the invention relates to a trailer which can be usedto transport a snowmobile or other tractive type vehicle on thehighways, and which can be converted to a sled to be towed behind thesnowmobile.

During the past several years, snowmobiles and like snow travelingvehicles have increased tremendously in popularity. Frequently, the userof the snowmobile will simply rent the snowmobile in a winter sportsarea rather than be bothered with transporting the snowmobile to andfrom the area where it can be used, because of the difficulties in thepast of transporting such a snowmobile, which usually weighs on theorder of 1,000 pounds.

However, it is necessary to transport a snowmobile on another vehicleover terrain where the snowmobile cannot be driven, because of areawithout snow, such as cleared highways. ln these instances, thesnowmobile must be loaded on a truck or trailer, transported to the siteof use, and then unloaded. Because the snowmobile is of substantialweight, 1,000 pounds or so, loading or unloading the snowmobile requireseither a loading ramp or other special equipment to load the snowmobileon the transporting vehicle.

Snowmobiles have a limited seating capacity. Therefore, where it isdesirable to carry cargo or more than two or three people, a trailermust be connected to the rear of the snowmobile. Where the conditionsare such that a snowmobile can be used, the trailerfor the snowmobilemust be a sled.

For highway use to transport the snowmobile, a trailer of the two-wheeltype, which can be towed byan automobile or small truck is highlydesirable. A towed trailer, however, must have its draw bar rigid withthe remainder of the trailer or else the trailer bedor frame will pivotfore and aft about the axis of the wheels. However, for loading avehicle such as a snowmobile on the trailer, it is desirable to tilt thebed or frame of the trailer rearwardly so the snowmobile or othervehicle can be driven directly onto the bed under its own power, andhence, separate loading equipment is not required. Such tilting of thetrailer frame or bed is accomplished quite readily in accordance withthis invention, even when the tongue is connected to the towing vehicleby pivotally connecting the tongue'or draw bar of the trailer to itsframe and by providing a selectively operable latch to permit the bed totilt rearwardly for loading. However, as soon as the snowmobile is movedto a position where its center of gravity and-that of the bed or frameof the trailer is forward of the axis of the trailer wheels, the bedwill tilt forward and there will be a tendency for the front of the bedto swing down into engagement with the ground. With the trailer of thisinvention a selectively operable lock or stop is actuable to a positionin which the trailer bed is permitted to tilt rearwardly for loadingwhile the tongue or draw bar is connected to the towing vehicle, but isprevented from tilting in a forward direction below a level in which thebed is substantially horizontal.

As stated above, when a two-wheel trailer is used on the highway, thetongue must be rigid with the wheels to prevent the trailer frame fromtilting around the axis of the wheels. However, a sled is stable foreand aft and when the skis or runners are in the ground engagingposition, and the trailer is towed by a snowmobile, a tongue rigid withthe frame is undesirable because the trailed sled will tend to eitherincrease or decrease the weight on the rear of the snowmobile as thevehicles pass over an undulating or bumpy snow covered terrain.Desirably, the draw bar should be free to pivot at its point ofconnection with the snowmobile, as well as about a horizontal axis atthe trailer. ln accordance with another aspect of this invention, thedraw bar of the trailer can be selectively locked against movementrelative to the trailer frame for use of the trailer as a highwayvehicle, but the draw bar can also be released for pivotal movementrelative to the frame for use of the trailer as a sled.

The convertible trailer of this invention includes a single axle withtwo ground engaging wheels. In addition, there are a pair of skis orrunners mounted at opposite sides of the vehicle frame for pivotalmovement from a lowered or ground engaging position in which the runnersare below the wheels to an upper or retracted position in which therunners are above the wheels. The conversion from a wheeled trailer to asnow sled is accomplished quite readily by merely releasing a series oflocks or latches which free the skis for movement to the upper or lowerpositions, and which are then actuated to lock the skis in the desiredpositions.

Advantageously, the locks or latches are so arranged that simpleinstructions to the user of the convertible trailer insure that thetongue or draw bar will be in its proper latched, unlatched, orpartially latched condition when the trailer is used respectively, forroad travel, as a sled, or for loading a snowmobile or other vehicle onthe trailer. In this respect, the locking or latch mechanisms at thefront of the trailer are so arranged that moving these latch mechanismsto a designated position for a particular use of the trailer lock thetongue in the appropriate latched, partially latched or unlatchedcondition. Hence, by following simple instructions, the user is assuredthat the trailer tongue is properly connected to the trailer for theparticular function to be performed by the trailer.

Were it not for the unique cooperating latch mechanism of this inventionvia which proper positioning of the tongue latch mechanism is assured,several possibly dangerous conditions could exist. For example, onecould inadvertently position the tongue latch in the position for use ofthe trailer as a sled while loading the snowmobile onto the vehicle. Aspreviously explained, when the trailer is used as a sled, the tongue isfree to pivot about its horizontal pivot connection with the trailerframe. Hence, as the snowmobile is driven onto the trailer and passesthe balance point of the frame, the frame would be free to tilt to afull forward position and strike the ground with possible damage to thesnowmobile or trailer. ln applicants arrangement, when the lock isproperly positioned for loading, the trailer frame is free to pivotrearwardly, but cannot pivot beyond an aligned position with the tonguein a forward direction. Advantageously, such loading is accomplishedwhile the draw bar is attached to the towing vehicle and hence, thesnowmobile loading can be performed by one man since movement of thetrailer is resisted by the towing vehicle.

latch which locks the skis or runners in the extended or retractedpositions also locks the tongue in the proper position for a particularuse of the trailer.

Some additional advantageous features of the trailer include a seatwhich is erectable to an upright position for transporting people whenthe trailer is used as a sled, yet is foldable to a flattened positionin which it reinforces the floor of the trailer and supports asnowmobile on the trailer. In addition, it will be appreciated that thetrailer of this invention requires no separate bed which is tiltablerelative to the frame, the pivot connection between the frame and thetongue provid ing for pivoting the frame about the wheels for loading asnowmobile.

correspondingly, an object of this invention is a trailer which isconvertible from a two-wheeled highway trailer particularly adapted totransport a snowmobile, to a sled which is adapted to be towed by thesnowmobile.

Another object is a convertible trailer having a rigid frame and apivotal connection between the frame and the draw bar of the trailer toprovide for loading the snowmobile or other vehicle on the trailer bytilting the frame while the trailer draw bar is attached to the towingvehicle.

Another object is a convertible trailer with a folding seat arrangementwhich is readily erectable to an occupant holding position when thevehicle is in use as a sled.

A further object is a vehicle convertible from a twowheeled trailer to asled in' which a unique latch mechanism is provided to assure that therelationship between the tongue and the trailer frame is proper for a vparticular use of the trailer.

A still further object is a trailer convertible from a highway vehicleto a sled in which a snowmobile can be loaded on the trailer by a singleperson as a result of the unique arrangement of the trailer whichpermits such loading while the trailer is connected to its towingvehicle. I v

A still further object is a unique trailer convertible from atwo-wheeled vehicle to a sled in which skis or runners are pivotallyconnected at opposite sides of the trailer frame for pivotal movementfrom a ground engaging position below the wheels of the trailer to aretracted position above the wheels of the trailer, a

unique latch mechanism cooperates with the skis to.

hold the skis in the desired positions and also cooperates with thetongue of the trailer to provide for locked, pivotal, or restrictedpivotal movement between the trailer and the tongue, and in whichthe,.,-

utility of the trailer both as a highway vehicle and as a sled embodiesthe most advantageous features of a vehicle for this particular use. 7 t

A not to be overlooked object is a convertible trailer of the typedescribed in which the trailer is rugged and 4 durable, isparticularly-adapted for use as a sled as well as a highway vehicle, isreadily loaded by driving a snowmobile oro'ther vehicle onto thetrailer, is relatively inexpensive to construct, and is extremelyreliable and safe to use.

Numerous other objects, advantages, and features of this invention willbecome apparent with reference to the drawings which form a part of thisspecification in which:

FIG. 1 is a side elevational view of the convertible trailer showing theskis in the ground engaging position and the seat erected for carryingpassengers;

FIG. 2 is a top plan view of the convertible trailer with the skis downand with the seat in its unfolded position;

FIG. 3 is a side elevational view of the trailer with the skies up andwith the trailer tilted for loading and unloading;

FIG. 4 is an enlarged partial top plan view of a front latch for thetrailer taken along line 4-4 of FIG. 1, showing the latch pin in itsposition for use of the trailer as a highway trailer;

FIG. 5 is a partial view in section taken along line 5- 5 of FIG. 4showing the latch pin in the highway trailer position;

FIG. 6 is a view corresponding to FIG. 5, and showing the latch pin inthe position for loading a snowmobile onto the trailer;

FIG. 7 is a view corresponding to FIG. 5, and showing the latch pin inits third position in which the tongue is released for use of thetrailer as a sled;

FIG. 8 is a view corresponding to FIG. 5, and showing the latch pin inits fourth position to completely release the skis for pivotal movementbetween the up and down positions;

FIG. 9 is a partial view taken along line 9-9 of FIG. 5 and showing thepivotal latch plate of the ski support; and

FIG. 10 is an enlarged partial view of a rear latch of the trailer.

Referring now to the drawings in detail, and particularly to FIG. 1,there is shown the convertible trailer 1 of this invention. Trailer 1includes a generally rectangular frame 2 having a draw bar or tongue 3connected to the frame adjacent its forward end at a pivot in the formof pins 4 which provide for pivotally connecting the frame to thetongue. Connected to the underside of frame 2 by springs 5 are wheels 6at opposite ends of a common axle 7.

A pair of skis or runners 8, are mounted respectively, for pivotalmovement about longitudinal axes adjacent each side edge of the framebetween the ground engaging position of FIGS. 1 and 2 and the retractedor upper position of FIG. 3.

Extending upwardly above the frame and secured to the respective siderails of the frame are a pair of inverted U-shaped hand grip bars 9. Asshown at FIGS. 1 and 2, hand grip: bars 9 are connected to sockets 10,mounted on the side edges of the respective side mem ,bers of theframe.

. and 2, it-will'be'seen that bottom panel l5 is secured to frame 2, ahinge 16 connects the front edge of panel 15 to the rear edge of panel14, a hinge 17 connects the front edge of panel 14 to the rear edgeofpanel l3, and a hinge 18 connects the rear edge of panel to panel 12.Formed in panel 12 are locking slots 19 which are parallel with eachother transversely of the trailer and are each of a size to receive thelocking arms 20 at the front edge of panel 13. Arms 20 are formed withoffset locking edges 22 which extend downwardly to prevent panels 13 and14 from moving forward relative to panel 12 when the seat is in theupright or erected position of FIG. 1. In addition, fastening connectors23 are provided on bars 9 to secure panel 12, which forms the seat backin the upright position of FIG. 1 to maintain the seat erect during useof the vehicle as a sled.

As shown at FIGS. 1 and 2, frame 2 is rectangular and elongated. Theframe is fabricated from structural members including angle iron siderails 26 and an angle iron front rail 27. There are also a plurality oftransversely extending parallel intermediate rails 28 (FIG. 5), each ofwhich takes the form of an inverted U-shaped channel. A sheet metalfloor 29 is mounted on and extends between the several side, front andintermediate rails to provide a support for panels 12-15, as well as forcargo, such as a snowmobile. Extending under frame 2 and of a lengthsomewhat greater than the width of the frame are parallel ski supportcross members 31 and 32. Front cross member 31 is located toward thefront of frame 2 adjacent the rear edge of draw bar 3, and rear crossmember 32 is located toward the rear of the frame behind wheels 6. Eachcross member takes the form ofa box-beam.

As shown at FIGS. 1-3, each ski is supported by a pair of spaced apartparallel support arms 34, 35 which are secured to the top face of theski and extend away from the ski in a direction perpendicular to theplane of the ski. As shown at FIG. 4, for the support arm 34, eachsupport arm is a structural member which is boxshaped, as viewed intransverse section. In addition, brace elements 36 and 37 are securedbetween support arm 34 and the nose of the ski, as well as betweensupport arm 34 and a portion of the ski rearwardly of the support arm.There is also a brace rod 38 which is secured to rear support arm 35 andextends at approximately a 45 angle toward ski 8 where it is secured tothe top of the ski at a location forwardly of arm 35. Arms 34 and 35 arespaced apart the same distance as cross members 31 and 32 and arepivotally connected to these cross members by the respective pivot pins39 and 40 which extend through the cross members. Pivot pins 39 and 40are aligned with each other and are outwardly of the side rails 26 ofthe frame.

As shown at FIGS. 4 and 9 for support arm 34, the rear and side walls ofeach arm are cut away, but the front wall 41 is left intact so itextends across the front face of cross member 31 and end 43 of the armis spaced from the bottom face of the cross member. An aligning plate 42is secured, as by welding, to the rear wall of arm 34. The distancebetween the front face of plate 42 and the rear face of front wall 41 isonly slightly greater than the width of the cross member. As shown atFIG. 4, pivot pin 39 extends through plate 42, cross member 31 and wall41 to pivotally connect arm 34 to the cross member. As shown at FIG. 9,there is a clearance space between end 43 of arm 34 and bottom surface44 of cross member 31 so arm 34 can pivot about pin 39. As shown at FIG.9, plate 42 is formed with a pair of apertures 46 and 47, each spacedthe same distance from and in the same horizontal plane as the axis ofpivot pin 39. Plate 42 is elongated, having a length greater than thewidth of arm 34, and a top edge 45 which is flush with the top surfaceof cross member 31 when the runners 8 are in the ground engagingposition.

As shown at FIGS. 1, 2 and 4, draw bar 3 is so constructed that rearportions 50 of draw bar 3 extend along opposite sides of the frame inparallel relation to the frame with only a slight clearance spacebetween the side edges of the frame and the inwardly facing surfaces ofthe rear portions 50. With reference to FIG. 5, each rear portion 50 hasa rear edge 51 which is closely adjacent front face 52 of cross member31, but is spaced sufficiently therefrom that frame 2 and tongue 3 canpivot relative to each other about the axis of pivot pin 4. As shown atFIG. 9, rear portion 50 of the tongue takes the form of an invertedU-shaped channel with downwardly extending sides. Mounted between thesides is a short length of angle iron 53 which is secured to the sidesby welding. Formed in the vertical leg of angle 53 is a bore 55 whichhas its top edge coplaner with the bottom surface 56 of the horizontalleg of the angle. Formed in cross member 31 are aligned bores 57 whichare in alignment with bore 55 when the tongue is horizontal and alignedwith the frame, as shown at FIGS. 1 and 5.

Mounted on side rail 26, to the rear of cross member 31, is a frontlatch assembly 60. Latch assembly 60 includes a mounting plate 61 whichis welded to side rail 26. A U-shaped latch pin support bracket 62 issecured to plate 61 as shown at FIGS. 4 and 5. Extending through alignedopenings formed in support bracket 62 is an elongated latch or lock pin63. As shown at FIG. 5, the rear portion of pin 63 terminates in adownwardly bent handle 64 which provides a hand grip for manipulatingthe pin. Pin 63 is constantly urged toward cross member 31 by the actionof compression spring 65 which seats at one end on a washer 66 connectedto the pin against forward movement, and at the other end on theforwardly facing surface 67 of bracket 62.

Also mounted on plate 61 and extending outwardly therefrom are aplurality of pin positioning abutment rods 7072. These abutment rodseach have a rearwardly extending end portion 73 over which handle 64 ofpin 63 can be moved to secure pin 63 against movement as a result ofshock or vibration. Pin 63 remains in engagement with a selected one ofabutment rods 70-72 by virtue of the action of spring 65 which urges thepin 63 forwardly toward cross member 31.

Rear latch member is similar to front latch member 60. As shown at FIG.10, the rear latch member includes a pin 81 which has a downwardly benthandle 82, like the handle 64 of pin 63. The assembly includes aU-shaped support bracket 83 through which the pin extends. The bracket83 is secured to a plate 85 welded to side rail 26. A stop rod 86 issecured to and projects outwardly from the plate and has a rearwardlyextending end 86 which provides for hooking the handle of pin 83 overthe abutment rod. Rear cross member 35 is provided with an opening toreceive the forward end of the pin, when the pin is in the forwardposition of FIG. 10.

With further reference to FIG. 5, it will be seen that cross rail 28extends acrossv the under surface 90 ofside rail 26 and engages thebottom surface .of floor. 29. Panel 13 is seen to lie flat againstfloor29.,

USE AND CONVERSION I tinuation of the frame, and the draw bar and framepro-' vide a continuous rigid unit for highway travel. The lock pins 63of the front latch assemblies 60, when in the position of FIG. 5,perform the dual function of securing draw bar 3 rigid with frame 2 andsecuring plate 42 against pivotal movement on pin 39 with the runners inup or-retracted position. With pin 63 in the position of FIG. 5, the pinextends through opening 46 of plate 42 (runner in the up position) andthe pin also extends through bores 57 of cross member 31 and bore 55 ofrear portion 50 of draw bar 3. With the pin in this position, plate 42and correspondingly, the runner support arm 34 are locked againstpivotal movement and in addition, draw bar 3 is held against pivotalmovement by the forward end of the pin which extends through the opening55.

To load a snowmobile on the trailer, the front end of the draw bar isfirst coupled to the usual ball type coupling 90 connected to the rearof a towing vehicle. Then, handle 64 of each lock assembly 60 is rotatedoutwardly to a generally horizontal position after which the handle ispulled rearwardly until it clears the end 73 of abutment rod 70,whereupon the handle is pushed inwardly so it engages behind abutmentrod 70, as shown at FIG. 6. In this position, pin 63 extends throughplate 42 and cross member 31 to a position beneath lower surface 56 ofangle 53. However, in this position the tip of the pin is no longer inbore 55 and hence, trailer frame 2 is free to pivot rearwardly relativeto draw bar 3 to the position of FIG. 3, in which rear end 91 of theframe engages the ground. By placing blocks both in front of and in backof wheels 6, one person acting alone can tilt the trailer to theposition of FIG. 3 merely by backing up the towing vehicle (pins 63 inthe FIG. 6 position) which will cause the frame to pivot rearwardly soend 91 engages the ground. Then, a snowmobile can be driven onto frame 2under its own power until it is fully on the trailer. Then, by removingthe blocks from behind wheel 6 in a gradual fashion, trailer frame 2will move toward a generally horizontal position. However, forwardtilting of the trailer beyond a horizontal position is prevented by theengagement of under surface 56 with the front end of lock pin 63.as soonas this surface engages the lock pin, as shown at FIG. 6. With thetrailer frame thus held in a horizontal position, handle 64 is againmanipulated so the pin 63 is returned to the FIG. 5 position in which itextends through opening 55. As previously explained, with, the

the snowmobile it is merely necessary to again manipulate pin 63 of eachfront latch assembly 60 to the position of FIG. 6, in which the pin iswithdrawn from opening 55. Then, it is merely necessary to verygradually back up the snowmobile until the center of gravity of thesnowmobile and frame is to the rear of axle 7. When this point isreached, the trailer will tilt to the FIG. 3 position (draw bar 3 stillattached to connector 90 of the towing vehicle) whereupon the snowmobilecan readily be backed off the trailer.

Trailer 1 can also be converted to a sled in a very rapid fashion. Thisis accomplished by manipulating pin 63 of each latch assembly 60 sohandle 64 is held in engagement with stop rod 72, as shown at FIG. 8.With pin 63 in this position, its nose is to the rear of plate 42 andcorrespondingly, support arm 34 is free to pivot. The pin 63, at theother side of the trailer, is also moved to the position of FIG. 8. Inaddition, pins 81 of rear latch assemblies 80 are pulled rearwardly andthe handles 82 of these pins are hooked over abutment rods 86, as shownin phantom lines at FIG. 10. With the several pins 63 and 81 in thereleased positions, runners 8 are free to pivot about the axes of pivotpins 39 and 40. The runners are then pivoted downwardly to the groundengaging positions and the trailer frame is lifted slightly so opening47 of plate 42 is aligned with pin 63. Handle 64 of each pin 63 is thenmanipulated so the handle hooks behind abutment rod 71. With handle 64-behind abutment rod 71, as shown at FIG. 7, pin 63 is withdrawn to aposition within cross member 31 and hence, draw bar 3 is free to pivotrelative to frame 2. This provides for free up and down pivotal movementof the trailer frame relative to the draw bar when the trailer is usedas a sled and is towed by the snowmobile. Since the runners form astable vehicle with no tendency to tilt fore and aft, a pivotalconnection between the draw bar and trailer frame is highly desirable topermi t the'trailer, now used as a sled, to tilt up and down relative tothe snowmobile which tows the trailer.

If it is desired to carry people on the trailer, when used as a sled, itis merely necessary to fold panels 12-15 to the erected or uprightposition of FIG. 1 and secure connectors 23 between hand bars 9 and back7 panel 12. By this simple expedient, a rigid seat for carpin in theFIG. 5 position, extending through opening 55, draw bar 3 and trailerframe 2 are locked together.

in a rigid condition for highway travel.

When trailer I is towed to the area where the snowmobile will be used,the snowmobile can readily be unloaded, and unloading is easier thanloading. To unload rying people on the sled is provided.

It will be observed with reference to FIGS. 6, 7 and 10, that latch pins63 and 81 prevent pivotal movement of plates 42 and therefore lock theskis in either the up or down positions when the trailer is usedrespectively, as a highway vehicle or as a sled. Pin 81 is moved to thephantom line position of F IG. 10 only when it is desired to move theskis from one position to the other. However, in all other positions ofthe pins, the runners are locked against pivotal movement.

In view of the foregoing, it will be apparent that the trailer of thisinvention is readily convertible from a highway vehicle to a sled andthat one person can quite easily load and unload a snowmobile from thetrailer. The aligning plates 42 of the several support arms 34, 35cooperate with lock pins 63 and 81 respectively, to assure that therunners are also returned to precisely the same horizontal loweredposition each time the vehicle is converted for use as a sled. Inaddition, since the pins 63 of the forward latch assemblies cooperatewith both the aligning plates for the runners, as well as the draw bar 3of the trailer, the user of the trailer is always assured that the skisare locked in position and that the proper connection between the drawbar and the trailer frame exists for a particular use of the trailer.Since the pins 63 of the forward latch assemblies are movable to onlyfour different positions, simple instructions to the user of the trailerwill enable the user to use the trailer as both a highway trailer, aswell as a sled with utmost efficiency and without danger of malfunction.Instructions with regard to the rear lock pins 83 are of course evenmore simple in that pin 83 is moved to the forward locking position atall times except when the runners are pivoted from one position toanother.

While a preferred embodiment of a convertible trailer has been shown anddescribed in detail, it is to be understood that numerous changesandmodifications can be made in the construction defined in thisapplication and in the appended claims without departing from theintended scope of the invention.

What is claimed is: l. A trailer convertible from a wheeled vehicle to asled comprising, in combination,

a frame; a pair of wheels connected to said frame; a pair of runners;mounting means mounting said runners outwardly beyond the sides of saidframe for pivotal movement to a ground engaging position below thewheels of the trailer, and I a retracted position above the wheels, andin which the runners are above the frame; lock means for each runnerbetween said frame and said mounting means and selectively positionableto a locked position to secure said runners in the ground engaging andretracted positions, and a released position in which the runners arefree for pivotal movement between said positions; a tongue connected tothe frame at a pivotal connection, said lock means for at least onerunner including a single actuator for selectively moving the lock meansto a first lock position to secure the runners in the retracted positionand to lock the tongue against pivotal movement, and a second lockposition to secure the runners in the ground engaging position and torelease the tongue for pivotal movement about its pivotal connection; anextension on the tongue extending along a side of said frame; at least aportion of the lock means disposed adjacent a portion of said tongue;said single actuator of said lock means being selectively positionableto a first position in which a runner lock of the lock means, with therunners in a retracted position, engages the mounting means for therunners to lock the runners in the retracted position, and a tongue lockof the lock means engages the tongue extension to fix the tongue againstpivotal movement about its pivotal connection, and

a second position in which the runner lock of the lock means, with therunners in a retracted position, engages the mounting means for therunners to lock the runners in the retracted position, and the tonguelock of the lock means engages an abutment of the tongue extension toprevent downward relative movement of the tongue and frame beyond agenerally aligned position with the frame while permitting upwardrelative movement of the tongue and frame so that a vehicle, such as asnowmobile, can be driven onto the frame by tilting the rear of theframe downwardly, but without danger of the frame pivoting forwardlybeyond the generally aligned position of the tongue with the frame.

2. A trailer according to claim 1 wherein the single actuator of saidlock means is further selectively positionable to an additional positionin which the runners are locked in the ground engaging position and thetongue is completely released for free pivotal movement relative to theframe at its pivotal connection.

3. A convertible trailer according to claim 2 wherein said singleactuator of said lock means is further positionable to an unlockedcondition in which the runners are released for pivotal movement betweenthe ground engaging and retracted positions.

4. A trailer convertible from a wheeled vehicle to a sled comprising, incombination an elongated frame;

wheels connected to said frame, said wheels having an axis of rotationand being in fixed non-adjusting relation to said frame;

a draw bar connected to the frame at a pivot connection and permittingthe frame to tilt about a transverse axis spaced from the wheels, thedraw bar having an extension adjacent a side of the frame;

first and second runners;

means mounting said runners on said frame for pivotal movement aboutaxes extending longitudinally of the frame and outwardly of the sides ofthe frame to aground engaging position below said wheels in which therunners are parallel to each other, and

a retracted position in which the wheels engage the ground;

single manually positionable means for preventing movement of the frontof the frame downwardly beyond an approximately aligned positionrelative to the draw bar while allowing the frame to tilt rearwardly soa vehicle can be moved into the tilted frame, and

for locking the frame to the draw bar against relative pivotal movement;

said single manually positionable means including an elongated pin, andabutment means cooperating with said pin to maintain the pin in apre-selected position; and said pin locks said draw bar to said frame byengaging said extension adjacent a side of the frame.

5. A trailer according to claim 4 wherein said manually positionablemeans is further positionable for i releasing said draw bar for freepivotal movement relative to the frame about its pivotal connection.

6. A trailer according to claim 4 wherein 7 said manually positionablemeans is further positionable for locking the runners in said groundengaging and retracted positions.

7. A convertible trailer according to claim 4 wherein said singlemanually positionable means is positionable to i a first position inwhich said runners are locked in their retracted positions and thetongue is generally aligned with and locked rigid with the frame,

a second position in which the runners are locked in the ground engagingposition and the frame is free to pivot at the draw bar pivotconnection,

a third position in which the runners are released for pivotal movementbetween the ground engaging and retracted positions, and

a fourth position in which the runners are latched in the retractedposition and the frame is free to pivot rearwardly only about the drawbar pivot connection.

8. A trailer convertible from a wheeled vehicle to a sled comprising, incombination,

a frame having sides;

a pair of wheels;

means connecting the frame to the wheels for pivotal movement about atransverse axis;

a pair of runners; 1

mounting means mounting said runners outwardly beyond the sides of saidframe for pivotal movement to v a ground engaging position below thewheels of the trailer, and

a retracted position above the wheels, and in which the runners areabove the frame; and

lock means for each runner between said frame and said mounting meansand selectively positionable 0 a locked position to secure said runnersin the ground engaging and retracted positions, and

a released position in which the runners are free for pivotal movementbetween said positions; and I a tongue connected to the frame at apivotal connection;

an extension of the tongue extending beside the frame;

said lock means for at least one runner including a runner lock, atongue lock, and a single actuator for selectively moving the runnerlock and the tongue lock to a first lock position in which the runnerlock of the lock means engages the mounting means of a runner to securethe runner in the retracted position and in which the tongue lock of thelock means simultaneously engages the tongue extension to secure thetongue against pivotal movement relative to the frame, and v a secondlock position in which the runner lock of the lock means engages themounting means of the runner to secure the runner in the ground engagingposition and in which the tongue .lock is spaced from the tongueextension to release the tongue for pivotal movement about its pivotalconnection.

9. A trailer convertible from a wheeled vehicle to a sledcomprising, incombination an elongated frame;

wheels connected to said frame, said wheels having an axis of rotationand being in fixed non-adjusting relation to said frame;

a draw bar connected to the frame at a pivot connection and permittingthe frame to tilt about a transverse axis spaced from the wheels, thedraw bar having an extension adjacent a side of the frame;

first and second runners;

means mounting said runners on said frame for pivotal movement aboutaxes extending longituv dinally of the frame and outwardly of the sidesof the frame to a ground engaging position below said wheels in whichthe runners are parallel to each other, and a retracted position inwhich the wheels engage the ground; single manually positionable means 1for preventing movement of the front of the frame downwardly beyond anapproximately aligned positionrelative to the draw bar while allowingthe frame to tilt rearwardly so a vehicle can be moved into the tiltedframe, and for locking the frame to the draw bar against relav tivepivotal movement; said extension of the draw bar includes means definingan aperture, and downwardly facing stop means; said positioning meanscooperates with said aperture to lock the draw bar to the frame; andsaid positioning means cooperates with said abutment to prevent downwardmovement of the frame relative to the draw bar. 10. A trailerconvertible from a wheeled vehicle to a sled comprising, in combinationan elongated frame; wheels connected to said frame, said'wheels havingan axis of rotation and being in fixed non-adjusting relation to saidframe; v a draw bar connected to the frame at a pivot connection andpermitting the frame to tilt about a transverse axis adjacent thewheels; first and second runners; means mounting said runners on saidframe for pivotal movement about axes extending longitudinally of theframe and outwardly of the sides of the frame to a ground engagingposition below said wheels in which the runners are parallel to eachother, and a retracted position in which the wheels engage the ground;single manually positionable means for preventing movement of the frontof the frame downwardly beyond an approximately aligned positionrelative to the draw bar while allowing the frame to tilt rearwardly soa vehicle can be moved into the tilted frame, and for locking the frameto the draw bar against relative pivotal movement;

said mounting means for each of said runners includes a structuralmember secured to a runner, said member including an alignment platerigid with the member, a pivot parallel to a side of said frame andpivotally connecting said structural member to the frame, and

means on said frame cooperating with said plate and 0

1. A trailer convertible from a wheeled vehicle to a sled comprising, in combination, a frame; a pair of wheels connected to said frame; a pair of runners; mounting means mounting said runners outwardly beyond the sides of said frame for pivotal movement to a ground engaging position below the wheels of the trailer, and a retracted position above the wheels, and in which the runners are above the frame; lock means for each runner between said frame and said mounting means and selectively positionable to a locked position to secure said runners in the ground engaging and retracted positions, and a released position in which the runners are free for pivotal movement between said positions; a tongue connected to the frame at a pivotal connection, said lock means for at least one runner including a single actuator for selectively moving the lock means to a first lock position to secure the runners in the retracted position and to lock the tongue against pivotal movement, and a second lock position to secure the runners in the ground engaging position and to release the tongue for pivotal movement about its pivotal connection; an extension on the tongue extending along a side of said frame; at least a portion of the lock means disposed adjacent a portion of said tongue; said single actuator of said lock means being selectively positionable to a first position in which a runner lock of the lock means, with the runners in a retracted position, engages the mounting means for the runners to lock the runners in the retracted position, and a tongue lock of the lock means engages the tongue extension to fix the tongue against pivotal movement about its pivotal connection, and a second position in which the runner lock of the lock means, with the runners in a retracted position, engages the mounting means for the runners to lock the runners in the retracted position, and the tongue lock of the lock means engages an abutment of the tongue extension to prevent downward relative movement of the tongue and frame beyond a generally aligned position with the frame while permitting upward relative movement of the tongue and frame so that a vehicle, such as a snowmobile, can be driven onto the frame by tilting the rear of the frame downwardly, but without danger of the frame pivoting forwardly beyond the generally aligned position of the tongue with the frame.
 2. A trailer according to claim 1 wherein the single actuator of said lock means is further selectively positionable to an additional position in which the runners are locked in the ground engaging position and the tongue is completely released for free pivotal movement relative to the frame at its pivotal connection.
 3. A convertible trailer according to claim 2 wherein said single actuator of said lock means is further positionable to an unlocked condition in which The runners are released for pivotal movement between the ground engaging and retracted positions.
 4. A trailer convertible from a wheeled vehicle to a sled comprising, in combination an elongated frame; wheels connected to said frame, said wheels having an axis of rotation and being in fixed non-adjusting relation to said frame; a draw bar connected to the frame at a pivot connection and permitting the frame to tilt about a transverse axis spaced from the wheels, the draw bar having an extension adjacent a side of the frame; first and second runners; means mounting said runners on said frame for pivotal movement about axes extending longitudinally of the frame and outwardly of the sides of the frame to a ground engaging position below said wheels in which the runners are parallel to each other, and a retracted position in which the wheels engage the ground; single manually positionable means for preventing movement of the front of the frame downwardly beyond an approximately aligned position relative to the draw bar while allowing the frame to tilt rearwardly so a vehicle can be moved into the tilted frame, and for locking the frame to the draw bar against relative pivotal movement; said single manually positionable means including an elongated pin, and abutment means cooperating with said pin to maintain the pin in a pre-selected position; and said pin locks said draw bar to said frame by engaging said extension adjacent a side of the frame.
 5. A trailer according to claim 4 wherein said manually positionable means is further positionable for releasing said draw bar for free pivotal movement relative to the frame about its pivotal connection.
 6. A trailer according to claim 4 wherein said manually positionable means is further positionable for locking the runners in said ground engaging and retracted positions.
 7. A convertible trailer according to claim 4 wherein said single manually positionable means is positionable to a first position in which said runners are locked in their retracted positions and the tongue is generally aligned with and locked rigid with the frame, a second position in which the runners are locked in the ground engaging position and the frame is free to pivot at the draw bar pivot connection, a third position in which the runners are released for pivotal movement between the ground engaging and retracted positions, and a fourth position in which the runners are latched in the retracted position and the frame is free to pivot rearwardly only about the draw bar pivot connection.
 8. A trailer convertible from a wheeled vehicle to a sled comprising, in combination, a frame having sides; a pair of wheels; means connecting the frame to the wheels for pivotal movement about a transverse axis; a pair of runners; mounting means mounting said runners outwardly beyond the sides of said frame for pivotal movement to a ground engaging position below the wheels of the trailer, and a retracted position above the wheels, and in which the runners are above the frame; and lock means for each runner between said frame and said mounting means and selectively positionable to a locked position to secure said runners in the ground engaging and retracted positions, and a released position in which the runners are free for pivotal movement between said positions; and a tongue connected to the frame at a pivotal connection; an extension of the tongue extending beside the frame; said lock means for at least one runner including a runner lock, a tongue lock, and a single actuator for selectively moving the runner lock and the tongue lock to a first lock position in which the runner lock of the lock means engages the mounting means of a runner to secure the runner in the retracted position and in which the tongue lock of the lock means simultaneouSly engages the tongue extension to secure the tongue against pivotal movement relative to the frame, and a second lock position in which the runner lock of the lock means engages the mounting means of the runner to secure the runner in the ground engaging position and in which the tongue lock is spaced from the tongue extension to release the tongue for pivotal movement about its pivotal connection.
 9. A trailer convertible from a wheeled vehicle to a sled comprising, in combination an elongated frame; wheels connected to said frame, said wheels having an axis of rotation and being in fixed non-adjusting relation to said frame; a draw bar connected to the frame at a pivot connection and permitting the frame to tilt about a transverse axis spaced from the wheels, the draw bar having an extension adjacent a side of the frame; first and second runners; means mounting said runners on said frame for pivotal movement about axes extending longitudinally of the frame and outwardly of the sides of the frame to a ground engaging position below said wheels in which the runners are parallel to each other, and a retracted position in which the wheels engage the ground; single manually positionable means for preventing movement of the front of the frame downwardly beyond an approximately aligned position relative to the draw bar while allowing the frame to tilt rearwardly so a vehicle can be moved into the tilted frame, and for locking the frame to the draw bar against relative pivotal movement; said extension of the draw bar includes means defining an aperture, and downwardly facing stop means; said positioning means cooperates with said aperture to lock the draw bar to the frame; and said positioning means cooperates with said abutment to prevent downward movement of the frame relative to the draw bar.
 10. A trailer convertible from a wheeled vehicle to a sled comprising, in combination an elongated frame; wheels connected to said frame, said wheels having an axis of rotation and being in fixed non-adjusting relation to said frame; a draw bar connected to the frame at a pivot connection and permitting the frame to tilt about a transverse axis adjacent the wheels; first and second runners; means mounting said runners on said frame for pivotal movement about axes extending longitudinally of the frame and outwardly of the sides of the frame to a ground engaging position below said wheels in which the runners are parallel to each other, and a retracted position in which the wheels engage the ground; single manually positionable means for preventing movement of the front of the frame downwardly beyond an approximately aligned position relative to the draw bar while allowing the frame to tilt rearwardly so a vehicle can be moved into the tilted frame, and for locking the frame to the draw bar against relative pivotal movement; said mounting means for each of said runners includes a structural member secured to a runner, said member including an alignment plate rigid with the member, a pivot parallel to a side of said frame and pivotally connecting said structural member to the frame, and means on said frame cooperating with said plate and manually positionable means to secure said runners in the ground engaging and retracted positions.
 11. A trailer according to claim 10 wherein said plate is apertured; said means on said frame is apertured; and said positioning means includes a pin cooperating with said apertures. 